Synfacts 2007(2): 0218-0218  
DOI: 10.1055/s-2006-955781
Polymer-Supported Synthesis
© Georg Thieme Verlag Stuttgart · New York

Diels-Alder Reaction of Triazoles with DMAD Catalyzed by Silica-Bound AlCl3

Contributor(s): Yasuhiro Uozumi, Yohei Oe
A. Díaz-Ortiz*, A. de Cózar, P. Prieto*, A. de la Hoz, A. Moreno
Universidad de Castilla-La Mancha, Ciudad Real, Spain
Further Information

Publication History

Publication Date:
23 January 2007 (online)

Significance

A microwave-assisted Diels-Alder reaction of 1,2,3-triazoles with dimethyl acetylenedicarboxylate (DMAD) catalyzed by silica-bound Lewis acid was achieved. Thus, the reactions of 1,2,3-triazoles with DMAD were carried out in the presence of silica-bound AlCl3 under solvent-free conditions with microwave irradiation for 20 minutes to afford the pyrazole-3,4-dicarboxylates in 38-94% yield. The pyrazoles were obtained by extrusion of the alkyl nitriles from the bicyclic intermediates, which were formed by the Diels-Alder cycloaddition of 1,2,3-triazoles with DMAD.